1. Field of the Invention
The present invention relates to a light module, and more particularly to a light module having good heat dissipation properties.
2. Description of the Prior Art
Fluorescent bulb, fluorescent tubes, or electric bulbs are used in traditional light devices as light source generators. In recent years, light-emitting diodes (LED) have been developed as light source generators. LED is a type of cold illumination and has the advantages of low power consumption, long device lifetime, no idling time, and quick response speed. In addition, since the LED also has the advantages of small size, suitability for mass production, and ease of fabrication as a tiny device or an array device, it has been widely applied in display apparatus and indicating lamps used in information, communication, consumer electronic products, and automotive industry, such as, cellular phones, as backlights of personal data assistants, outdoor traffic signal lamps or various outdoor displays, even as a components in the highly popular liquid crystal displays.
FIGS. 1 and 2 are each a cross section diagram illustratively showing a conventional LED module, respectively. As shown in FIG. 1, the conventional LED module includes a substrate 10, a plurality of LED units 12 positioned above the substrate 10, and an encapsulating material layer 14 disposed on the LED unit 12. As shown in FIG. 2, the conventional LED module includes a substrate 16, an insulating layer 18, a printed circuit board 20 positioned above the substrate 16, and a plurality of LED package bodies 22 disposed on the printed circuit board 20 and electrically connected to the printed circuit board 20. The LED package body 22 is constructed by forming the encapsulating material layer 24 via molding or sealant injection, and the entire LED module is then formed by aggregating each of the LED package bodies 22 on the substrate 16.
However, in conventional techniques for assembling light modules, such as the above mentioned LED modules, the substrate is generally a lead frame or a printed circuit board (PCB), and a plural LED chips are fixed onto the substrate, or a plurality of LED packages are combined, for forming a module or a light engine. The LED chips or package with the substrate only connect to heat dissipating fins for heat dissipation. Thus, uneven heat dissipation and local hot spots tend to occur. The resulting local high temperature will lead the LED to have disadvantages of a short lifetime, uneven color, or uneven light intensity.
Therefore, a novel light-emitting module having uniform heat dissipation for avoiding local hot spots is still needed.